Patients at high-risk of developing pulmonary complications such as pneumonia following coronary artery bypass graft surgery can reduce their risk through breathing exercises and respiratory muscle training before the operation, according to a study in the October 18 issue of JAMA.

Despite improvements in coronary artery bypass graft (CABG) surgery and care around the time of the operation, the rate of postoperative pulmonary complications (PPCs) has remained stable, possibly because CABG surgery is now performed in more fragile (high-risk) patients at greater risk of PPCs. Postoperative pulmonary complications continue to have an effect on patient illness and risk of death, length of hospital stay, and overall use of resources, according to background information in the article. The prehospitalization period before CABG surgery could be used to improve a patient's pulmonary condition. The effectiveness of preoperative inspiratory (breathing in) muscle training (IMT) in reducing the incidence of PPCs in high-risk patients undergoing CABG surgery has previously not been determined.

In this study, IMT consisted of preoperatively individualized, tailored exercises, 7 times a week, for at least 2 weeks before the actual date of surgery, and included education in breathing techniques; forced expiration techniques; and use of a spirometry, to measure the capacity of the lungs.

Erik H. J. Hulzebos, P.T., M.Sc., of the University Medical Center, Utrecht, the Netherlands and colleagues examined the effectiveness of preoperative physical therapy, including IMT, on the incidence of PPCs, especially pneumonia, in patients at high risk of developing PPCs who underwent CABG surgery. Enrollment in the randomized clinical trial was conducted between July 2002 and August 2005. Of 655 patients referred for elective CABG surgery, 299 (45.6 percent) met criteria for high risk of developing PPCs, of whom 279 were enrolled and followed up until discharge from hospital. Patients were randomly assigned to receive either preoperative IMT (n = 140) or usual care (n = 139). Both groups received the same postoperative physical therapy.

In patients at high risk of developing PPCs, IMT resulted in significant improvement in average inspiratory muscle strength and respiratory muscle endurance.

After CABG surgery, PPCs were present in 25 (18.0 percent) of 139 patients in the IMT group and 48 (35.0 percent) of 137 patients in the usual care group, a reduction in incidence of PPCs of 48 percent. The incidence of pneumonia was 6.5 percent in the IMT group and 16.1 percent in the usual care group. The median (middle value) duration of postoperative hospitalization was 7 days (range, 5-41 days) in the IMT group vs. 8 days (range, 6-70 days) in the usual care group.

"We found that preventive physical therapy with IMT administered to patients at high risk of PPCs before CABG surgery was associated with an increase in inspiratory force and a decrease in the incidence of PPCs and length of hospitalization. We consider this to be an important presurgical intervention that appears to be effective at reducing morbidity," the authors conclude.



(JAMA. 2006;296:1851-1857.)

Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Contact: Erik H. J. Hulzebos
JAMA and Archives Journals